Stress response in Pectobacterium atrosepticum SCRI1043 under starvation conditions: Adaptive reactions at a low population density

The adaptive reactions of plant pathogenic bacterium Pectobacterium atrosepticum SCRI1043 under starvation conditions were studied. The main emphasis was given to the peculiarities of stress responses depending on the bacterial population densities. When bacteria were subjected to starvation at high population densities (107-109CFUml-1), their adaptive reactions conformed to the conventional conception of bacterial adaptation related to autolysis of part of the population, specific modification of cell ultrastructure, activation of expression of stress responsive genes and acquiring cross protection against other stress factors. In contrast, at low initial population densities (103-105CFUml-1), as described in our recent work, the cell density increased due to multiple cell division despite the absence of exogenous growth substrate. Here we present data that demonstrate that such unconventional behavior is part of a stress response, which provides increased stress tolerance while retaining virulence. Cell morphology and gene expression in high- and low-cell-density starving Pba cultures were compared. Our investigation demonstrates the existence of alternative adaptive strategies enabling pathogenic bacteria to cope with a variety of stress factors, including starvation, especially necessary when residing outside of their host. © 2013 Institut Pasteur

Alternative scenarios of starvation-induced adaptation in Pectobacterium atrosepticum

© 2016 Institut Pasteur.Bacteria have high adaptive potential that ensures their survival during various environmental challenges. To adapt, bacteria activate a physiological program of stress response that makes them able to persist under adverse conditions. The present study sought to examine the ability of a particular bacterial species to induce a stress response in alternative scenarios. Cells of the phytopathogenic microorganism Pectobacterium atrosepticum were taken as a model. The cells were exposed to starvation in different physiological states (actively growing exponential phase and stationary phase cells), and the resulting starving cultures were monitored using CFU counting, quantitative PCR and electron microscopy. When exponential phase cells were subjected to starvation, the nucleoids of the cells became condensed and their DNA was detected by qPCR less effectively than that of cells growing in nutrient-rich medium, or stationary phase cells after starvation. Exponential phase cells subjected to starvation showed increased expression of genes encoding DNA binding histone-like proteins, whereas, in cultures inoculated by stationary phase cells, cell-wall-deficient forms that were inefficient at colony forming and that had a non-culturable phenotype were formed. The cell-wall-deficient forms displayed reduced expression of genes encoding synthases of cell wall components

Pathogen-induced conditioning of the primary xylem vessels – a prerequisite for the formation of bacterial emboli by Pectobacterium atrosepticum

© 2016 German Botanical Society and The Royal Botanical Society of the NetherlandsRepresentatives of Pectobacterium genus are some of the most harmful phytopathogens in the world. In the present study, we have elucidated novel aspects of plant–Pectobacterium atrosepticum interactions. This bacterium was recently demonstrated to form specific ‘multicellular’ structures – bacterial emboli in the xylem vessels of infected plants. In our work, we showed that the process of formation of these structures includes the pathogen-induced reactions of the plant. The colonisation of the plant by P. atrosepticum is coupled with the release of a pectic polysaccharide, rhamnogalacturonan I, into the vessel lumen from the plant cell wall. This polysaccharide gives rise to a gel that serves as a matrix for bacterial emboli. P. atrosepticum-caused infection involves an increase of reactive oxygen species (ROS) levels in the vessels, creating the conditions for the scission of polysaccharides and modification of plant cell wall composition. Both the release of rhamnogalacturonan I and the increase in ROS precede colonisation of the vessels by bacteria and occur only in the primary xylem vessels, the same as the subsequent formation of bacterial emboli. Since the appearance of rhamnogalacturonan I and increase in ROS levels do not hamper the bacterial cells and form a basis for the assembly of bacterial emboli, these reactions may be regarded as part of the susceptible response of the plant. Bacterial emboli thus represent the products of host–pathogen integration, since the formation of these structures requires the action of both partners

Introduction of Information Technologies in Supply Chain Management

The article addresses the development of mobile applications designed to automate business processes in logistics. It examines the challenges associated with optimizing the workflow, finding the critical path of multiple supply chains, as well as the possibility for sales agent to quickly track the location of goods online.Статья посвящена разработке мобильного приложения, предназначенного для автоматизации бизнес-процессов в логистике. В данной работе рассматриваются задачи, связанные с оптимизацией документооборота, нахождения критического пути из множества сетей поставок, а также возможности торгового агента оперативно отслеживать местоположение товаров в режиме онлайн

Transcriptome profiling helps to identify potential and true molecular switches of stealth to brute force behavior in Pectobacterium atrosepticum during systemic colonization of tobacco plants

© 2018, Koninklijke Nederlandse Planteziektenkundige Vereniging. In the present study, we have monitored the process of systemic plant colonization by the plant pathogenic bacterium Pectobacterium atrosepticum (Pba) using RNA-Seq analysis in order to compare bacterial traits under in planta and in vitro conditions and to reveal potential players that participate in switching from stealth to brute force strategy of the pathogen. Two stages of tobacco plant colonization have been assayed: i) the initial one associated with visually symptomless spread of bacteria throughout the host body via primary xylem vessels where bacterial emboli were formed (stealth strategy), and ii) the advanced stage coupled with an extensive colonization of core parenchyma and manifestation of soft rot symptoms (brute force strategy). Plant-inducible genes in Pba and potential players switching the pathogen’s behavior were revealed. Genes from the cfa locus responsible for the production of coronafacic acid displayed the strongest induction in the asymptomatic zone relative to the symptomatic one and were shown experimentally to act as the true strategy “switchers” of Pba behavior in planta. Surprisingly, cfa genes appeared to be unnecessary for establishment of the asymptomatic stage of plant colonization but were required for the transition to soft-rot-associated symptomatic stage coupled with over-induction of jasmonate-mediated pathway in the plant

Pectobacterium atrosepticum exopolysaccharides: Identification, molecular structure, formation under stress and in planta conditions

© The Author 2017. Published by Oxford University Press. All rights reserved. In the present study, we identified exopolysaccharides of the harmful phytopathogenic bacterium Pectobacterium atrosepticum SCRI1043 and characterized the molecular structure of these polymers. The synthesis of the target polysaccharides was shown to be induced under starvation conditions. Moreover, intensive accumulation of exopolysaccharides occurred during the colonization by bacteria of the xylem vessels of infected plants, where microorganisms formed specific 3D "multicellular" structures-bacterial emboli. Thus, the identified polymers are likely to be involved in the adaptation and virulence of bacteria of Pectobacterium genus

Human Mesenchymal Stem Cells as a Carrier for a Cell-Mediated Drug Delivery

A number of preclinical and clinical studies have demonstrated the efficiency of mesenchymal stromal cells to serve as an excellent base for a cell-mediated drug delivery system. Cell-based targeted drug delivery has received much attention as a system to facilitate the uptake a nd transfer of active substances to specific organs and tissues with high efficiency. Human mesenchymal stem cells (MSCs) are attracting increased interest as a promising tool for cell-based therapy due to their high proliferative capacity, multi-potency, and anti-inflammatory and immunomodulatory properties. In particular, these cells are potentially suitable for use as encapsulated drug transporters to sites of inflammation. Here, we studied the in vitro effects of incorporating synthetic polymer microcapsules at various microcapsule-to-cell ratios on the morphology, ultrastructure, cytokine profile, and migration ability of human adipose-derived MSCs at various time points post-phagocytosis. The data show that under appropriate conditions, human MSCs can be efficiently loaded with synthesized microcapsules without damaging the cell’s structural integrity with unexpressed cytokine secretion, retained motility, and ability to migrate through 8 ?m pores. Thus, the strategy of using human MSCs as a delivery vehicle for transferring microcapsules, containing bioactive material, across the tissue–blood or tumor–blood barriers to facilitate the treatment of stroke, cancer, or inflammatory diseases may open a new therapeutic perspective

Formation renal function in children born prematurely

A premature baby needing resuscitation after birth, is exposed to damaging factors affecting the entire body, including the kidneys. Aim — analysis of current data on the issue of the formation of kidney function in children born prematurely. Materials and methods. The review publications domestic and foreign authors studied data from randomized clinical and epidemiological studies. Results and discussion. Events intensive care, which include mechanical ventilation, infusion therapy, parenteral nutrition, intravenous drugs, lead to an increased load on the immature kidney premature baby in the neonatal period. A special risk factor for preterm is still imperfect glomerular and tubular function, renal large capillary surface, high renal blood flow, inadequate regulation of acid-base balance and the ability to concentrate, are under the influence of external loads become insolvent. Under the influence of damaging factors on the kidney nephron deficit increases the risk of further decline in kidney function. It is assumed that no additional nephrons deficit is not negative factors leads to chronic diseases in the future. Conclusion. Analyzing conducted research on the formation of kidney function in children born prematurely, it can be assumed that children with a gestational age less than 32 weeks and weighing less than 1500 grams at birth, who are exposed to adverse environmental factors on the developing buds in the perinatal and neonatal periods. They are in the zone of risk of chronic disease of the kidneys in later life

New early non-invasive biomarkers for acute kidney injury in critically ill full-term neonatal infants

Critically ill neonates are at high risk for acute kidney injury (AKI). Objective: to estimate the clinical and diagnostic value of urinary neutrophil gelatinase-associated lipocalin (NGAL) 2, interleukin-18 (IL-18), and kidney injury molecule-1 (KIM-1) levels in diagnosing AKI in critically ill full-term newborn infants. Subjects and methods. A study group consisted of 86 critically ill full-term neonates who were divided into 2 subgroups according to their blood creatinine levels at the age of less than 2 days of life: 1) creati-nine >1,5 mg/dl (и=12) and 2) creatinine <1,5 mg/dl (и=74). A control group included 26 healthy full-term newborns. Results. The incidence of AKI was 14%. Its clinical sign was urine output less thanl, 5 ml/kg/h(/K0,001). On days 3—5 of life, Subgroup 1 showed urinary NGAL values that were twice higher than those in Subgroup 2; on days 10-14, there was a 1,5-fold decrease in this indicator, but it remained at a rather high level in the control group. On days 3-5 of life, the levels of urinary KIM-1 were thrice higher in Subgroup 1 than those in Subgroup 2; on days 18—21, the difference between them was almost 7 times higher (/K0,01). On days 3—5 of life, Subgroup 1 displayed urinary IL-18 values that were twice higher than those in Subgroup 2; on days 18—21, the difference remained at the same level (/K0,05). Conclusion. Determination of urinary NGAL, IL-18, and KIM-1 levels is recommended for the early non-invasive diagnosis of AKI in critically ill full-term neonates. Urinary NGAL and KIM-1 are markers of poor outcomes; IL-18 is a marker of the aggressive nephrotoxicity of the therapy performed

COVID-19 in children: the accumulated experience?

The article presents the main issues of COVID-19 in children, concerning the epidemiology, clinical course and risk groups. Despite the fact that COVID-19 affects children less often and it usually has a mild or asymptomatic course, there are severe and extremely severe courses especially in children and adolescents with certain risk factors (such as immunodeficiency, oncological diseases, obesity or other chronic diseases). The authors describe a clinical case of the severe course of COVID-19 in a 14-year-old teenager